DESCRIPTION (provided by investigator): A major public health challenge is to better understand and predict how anthropogenic environmental changes affect vector-borne diseases. In response to rapidly expanding human populations many countries in the Middle East are developing unprecedented large-scale agricultural irrigation systems to increase food production. In Upper Egypt, there are major concerns that projects underway to transform desert environments for irrigated agriculture in the Old Nile Valley (about 70,000 acres) and in the Toshka Valley (nearly 1 million acres) will substantially increase the risks of important mosquito-borne diseases. These projects are creating new suitable habitats for vector populations and facilitating the migration and establishment of large human and animal populations. This project addresses the need to determine how land use and the large-scale transformation of desert environments for irrigated agriculture in Upper Egypt affects the risk and transmission dynamics of the well-established West Nile virus (WNV) and the epidemic potential of Rift Valley fever virus (RVFV) and malaria. There are 3 specific aims: 1) determine how land use and the transformation of desert environments for irrigated agriculture affect the ecology and behavior of mosquito species and their potential for pathogen transmission, 2) evaluate the extent of WNV in birds and RVFV in domestic livestock and assess how geographic heterogeneity in animal host diversity and relative abundance affects the potential for pathogen transmission, and 3) employ eco-epidemiological modeling approaches to assess the impact of environmental changes on the complex dynamics and risks of mosquito-borne diseases. This project represents a unique opportunity to prospectively quantify vector-host-pathogen population dynamics in the context of unprecedented large-scale environmental perturbations in desert environments. The outcomes of this project will contribute to integrated disease surveillance and control programs in Egypt as well as other areas of the Middle East.